This invention relates to the employment of N,N-dimethylglycine to enhance the immune response of man or animals to an immunogen (vaccine) or potentiate defense mechanisms of man and animals to attack by infectious disease agents such as bacteria, viruses, fungi, protozoa or helminths (worms).
Immunization of man and animals by artifical means has several purposes. The main aim, however, is prophylactic immunization against disease, done usually by a harmless vaccine to accomplish stimulation of the immune system that otherwise might be done by uncontrolled disease with the possibility of death occurring to the host.
Prophylactic immunization to prevent clinical infection by bacteria, viruses, etc. involves production of antibody, a protein secretion of plasma cells to the vaccine administered. This antibody should preferably be long lasting, and the plasma cells, or their progeny generating it should produce more and larger quantities of the antibody to meet the challenge of the invading microorganism, when this occurs.
Also related cells, neutrophils, macrophages and lymphocytes must respond and perform phagocytosis (neutrophils and macrophages) and produce cytokines (secretions of lymphocytes and macrophages) which also inactivate, or destroy, the microorganism. The latter is referred to as cellular mediated immunity (CMI). Thus we have two limbs of the immune response -
1. Humoral (antibody) immunity produced by plasma cells; PA0 2. Cellular Mediated (cytokines) immunity produced by macrophages and lymphocytes.
Other plasma components, such as complement, properdin, interferon, etc. are involved in the orchestration of the humoral and cellular mediated immune response of the host, but since they are not involved directly here, will not be elaborated on.
When non-viable agents are used as a vaccine, it is essential to compensate for the fact that the non-living bacteria, or their antigens are not going to elicit as good a humoral or CMI response as the living agent. Such a compensating agent is known as a immuno-adjuvant. By definition (World Health Report--Geneva, 1976) adjuvants are substances that are incorporated into, or injected simultaneously with an antigen, to potentiate non-specifically the ensuing immune response.
(In the strictest interpretation of this definition, our invention is not an adjuvant since N,N-dimethylglycine is not administered parenterally, to man or animals, along with antigen in the experiments described vide infra. It is, however, given orally, as an immuno-modulator, to enhance the immunologic response; therefore, the WHO definition is broadened somewhat here, to allow the word "adjuvant" to be used.)
A great deal of research has been carried out, particularly in the Soviet Union on a substance which the Russian researchers call calcium pangamate, (the calcium salt of pangamic acid), which has the following structure: ##STR1##
Pangamic acid may be considered to be the ester compound formed between one unit of gluconic acid and one unit of N,N-dimethylglycine. Indeed, water hydrolysis yields one molecule each of gluconic acid and N,N-dimethylglycine. This hydrolysis is illustrated below: ##STR2##
When pangamic acid is ingested, it is expected that any effect obtained which could not be attributed to pangamic acid would be the result of increased presence in the body of the expected metabolites N,N-dimethylglycine and gluconic acid, and/or further metabolic products thereof. Furthermore, it is believed that the composition of calcium pangamate used by the Russians is actually a mixture of the calcium salt of pangamic acid, calcium gluconate and N,N-dimethylglycine. It is believed that the proportion, by weight, of calcium pangamate: calcium gluconate: N,N-dimethylglycine in the Russian formulation would be about 70-75: 12.5-15: 12.5-15. In this regard, see U.S. Pat. No. 3,907,869 to Bukin et al, particularly column 2, lines 8-18. It is not certain how this composition relates to Calgam exhibited at the Montreal Expo in 1967, exported by v/o Medexport, USSR, believed to be at the present time a mixture of calcium gluconate, N-N-dimethylglycine and polymeric sugars. The inventors have reviewed extensive areas of the Russian literature on the Russian pangamic acid work, but have not found any disclosure therein believed relevant to the immuno-response enhancement effect of N,N-dimethylglycine as claimed herein. See "Effectiveness of Calcium Pangamate Introduced to Vaccinated and Irradiated Animals" by Nizametdinova in Reports of the Kazan Veterinary Institute Vol 112, pp 100-104 (1972) where calcium pangamate is described as being injected into animals which have been vaccinated and then irradiated at a dosage sufficient to cause radiation sickness. The Russian workers conclude that the immunized and subsequently irradiated animals exhibited a normalization of immunological activity following calcium pangamate administration, as compared to a control group, which did not. It is interesting to note that although the Russians in one experiment are stated to have included a test group of animals which were vaccinated and then injected with calcium pangamate (not irradiated), no data thereof is disclosed. Thus, no information on calcium pangamate potentiation of the normal immune response is proffered. The present invention is not concerned with treatment of radiation sickness in irradiated animals but enhancing the natural immuno response of a living organism.
U.S. Pat. No. 3,392,195 to Galat discloses the use of glycine as an antacid.
U.S. Pat. No. 2,907,781 to Hermelin discloses the use of an aluminum salt of glycine in treatment of stomach ulcers.
U.S. Pat. No. 3,167,475 to Gottfried et al relates to the use of an alcohol derivative of N,N-dimethylglycine in the treatment of allergies.
U.S. Pat. No. 2,710,876 to Krebs et al discloses the reaction of N,N-dimethylglycine with gluconic acid to yield pangamic acid.
The non-Russian literature is replete with articles concerning N,N-dimethylglycine's participation in metabolic processes, particularly the 1-carbon cycle involving choline and betaine. Betaine yields N,N-dimethylglycine after transferring one methyl group to homocysteine, (see Principles of Biochemistry, White et al, McGraw-Hill, 6th Ed. 1978, p. 695.) However, the literature reviewed by the present inventors does not relate to the immuno response characteristics now found for N,N-dimethylglycine.
Lastly, some of the work on which the present invention is based is disclosed in B-15: The "Miracle Vitamin" by Brenda Forman (Fred Jordan Books/Grosset and Dunlap, New York, 1979--See pages 149-151) and was reported in the Proceedings of the Annual Meeting of the American Society for Microbiology, Southeastern and South Carolina Branches, Atlanta, Ga., November 8-9, 1979.